Abdominal treatment systems, delivery devices, and methods

ABSTRACT

A reduced-pressure abdominal treatment device is presented that has a plurality of liquid-impermeable layers with a foam spacer between two of the liquid-impermeable layers. The plurality of liquid-impermeable layers have a coextensive area A1. The foam spacer has a plan-view area A2. A2 is less than 80% of A1 (i.e., A2&lt;0.8A1). The foam spacer is configured such that, under reduced pressure, a target fluid removal zone experiences reduced-pressure vectors over an angle theta (θ) that is typically 360 degrees for a majority of locations in the target fluid removal zone. Applying 360 degrees of reduced pressure helps avoid blockage. The plurality of liquid-impermeable layers may be bonded for various effects. Other devices, systems, and methods are disclosed.

RELATED APPLICATIONS

This application is a Divisional of U.S. patent application Ser. No.14/989,533, filed Jan. 6, 2016, which is a Divisional of U.S. patentapplication Ser. No. 13/903,818, filed May 28, 2013, now U.S. Pat. No.9,259,356, which is a Divisional of U.S. patent application Ser. No.13/043,987, filed Mar. 9, 2011, now U.S. Pat. No. 8,469,935, whichclaims the benefit, under 35 USC § 119(e), of the filing of U.S.Provisional Patent Application Ser. No. 61/312,990, entitled “AbdominalTreatment Systems, Delivery Devices, and Methods,” filed Mar. 11, 2010,which is incorporated herein by reference for all purposes.

BACKGROUND

The present disclosure relates generally to medical treatment systems,and more particularly, to abdominal treatment systems, delivery devices,and methods for treating an abdominal cavity using reduced pressure.

Depending on the medical circumstances, reduced pressure may be usedfor, among other things, reduced-pressure therapy to encouragegranulation at a tissue site or for draining fluids at a tissue site. Asused herein, unless otherwise indicated, “or” does not require mutualexclusivity. Both reduced-pressure therapy and drainage with reducedpressure often involve manifolding, or distributing, reduced pressure tothe tissue site.

SUMMARY

According to an illustrative, non-limiting embodiment, an abdominaltreatment delivery device for distributing reduced pressure to a tissuesite in an abdominal cavity and removing fluids includes a plurality ofliquid-impermeable layers that are proximate to one another and a foamspacer disposed between at least two layers of the plurality ofliquid-impermeable layers. The plurality of liquid-impermeable layershas a coextensive area A₁ and the liquid-impermeable layers arefenestrated. The foam spacer has a plan-view area A₂, and A₂ is lessthan 80% of A₁ (i.e., A₂<0.8A₁). The foam spacer is configured andlocated such that, under reduced pressure, a target fluid removal zoneexperiences reduced-pressure vectors over an angle theta (θ) that is 360degrees for a majority of locations in the target fluid removal zone.

According to another illustrative, non-limiting embodiment, a system fortreating an abdominal cavity with reduced pressure includes an abdominaltreatment device for distributing reduced pressure to a tissue site anda reduced-pressure source. The reduced-pressure source is fluidlycoupled to the abdominal treatment device. The abdominal treatmentdevice includes a plurality of liquid-impermeable layers that areproximate to one another and a foam spacer disposed between at least twolayers of the plurality of liquid-impermeable layers. The plurality ofliquid-impermeable layers has a coextensive area A₁ and is fenestrated.The foam spacer has a plan-view area A₂, and A₂ is less than 80% of A₁(i.e., A₂<0.8A₁). The foam spacer is configured such that, under reducedpressure, a target fluid removal zone experiences reduced-pressurevectors over an angle theta (θ) that is 360 degrees for a majority oflocations in the target fluid removal zone.

According to another illustrative, non-limiting embodiment, a method ofmanufacturing an abdominal treatment device includes the steps ofproviding a plurality of liquid-impermeable layers that are fenestratedand disposing a foam spacer between at least two layers of the pluralityof liquid-impermeable layers. The plurality of liquid-impermeable layershas a coextensive area A₁. The foam spacer disposed between at least twolayers of the plurality of liquid-impermeable layers has a plan-viewarea A₂, and A₂ is less than 80% of A₁ (i.e., A₂<0.8A₁). The foam spaceris configured and located such that, under reduced pressure, a targetfluid removal zone experiences reduced-pressure vectors over an angletheta (θ) that is 360 degrees for a majority of locations in the targetfluid removal zone.

According to another illustrative, non-limiting embodiment, a method oftreating a tissue site in an abdominal cavity includes the steps of:opening the abdominal cavity to form an open cavity; deploying withinthe abdominal cavity an abdominal treatment delivery device; deploying areduced-pressure connector subsystem; and deploying a sealing member toform a fluid seal over the open cavity. The method further includesfluidly coupling the reduced-pressure connector subsystem to areduced-pressure source and activating the reduced-pressure source. Theabdominal treatment device includes a plurality of liquid-impermeablelayers that are proximate to one another and a foam spacer disposedbetween at least two layers of the plurality of liquid-impermeablelayers. The plurality of liquid-impermeable layers has a coextensivearea A₁ and is fenestrated. The foam spacer has a plan-view area A₂, andA₂ is less than 80% of A₁ (i.e., A₂<0.8A₁). The foam spacer isconfigured and located such that, under reduced pressure, a target fluidremoval zone experiences reduced-pressure vectors over an angle theta(θ) that is 360 degrees for a majority of locations in the target fluidremoval zone.

Other features and advantages of the illustrative embodiments willbecome apparent with reference to the drawings and detailed descriptionthat follow.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic diagram with a portion in cross section of anillustrative system for treating an abdominal cavity;

FIG. 2 is a schematic, plan view of an illustrative abdominal treatmentdevice;

FIG. 3 is a schematic, cross-sectional view of a portion of theillustrative abdominal treatment device of FIG. 2 taken along line 3-3;

FIG. 4A is a schematic plan view of a portion of an abdominal treatmentdevice;

FIG. 4B is a schematic cross section of a portion of the abdominaltreatment device of FIG. 4A taken along line 4B-4B;

FIG. 5 is another schematic, plan view of another illustrative abdominaltreatment device;

FIG. 6 is a schematic, plan view of another illustrative abdominaltreatment device;

FIG. 7 is a schematic, exploded perspective view of another illustrativeabdominal treatment device; and

FIG. 8 is a schematic, plan view of the illustrative abdominal treatmentdevice of FIG. 6 shown with an additional feature.

DETAILED DESCRIPTION

In the following detailed description of the non-limiting, illustrativeembodiments, reference is made to the accompanying drawings that form apart hereof. These embodiments are described in sufficient detail toenable those skilled in the art to practice the invention, and it isunderstood that other embodiments may be utilized and that logicalstructural, mechanical, electrical, and chemical changes may be madewithout departing from the spirit or scope of the invention. To avoiddetail not necessary to enable those skilled in the art to practice theembodiments described herein, the description may omit certaininformation known to those skilled in the art. The following detaileddescription is, therefore, not to be taken in a limiting sense, and thescope of the illustrative embodiments are defined only by the appendedclaims.

Referring now to FIGS. 1 and 2, an illustrative embodiment of a system100 for treating an abdominal cavity 102 is presented. The system 100includes an abdominal treatment device 104. The system 100 and theabdominal treatment device 104 are for treating a tissue site 106 of apatient. The tissue site 106 may be the bodily tissue of any human,animal, or other organism. In this illustrative embodiment, the tissuesite 106 includes tissue in a body cavity, and in particular theabdominal cavity 102. The tissue site 106 includes the abdominalcontents 108 or tissue that is proximate the abdominal cavity 102.Treatment of the tissue site 106 may include removal of fluids, e.g.,ascites, protection of the abdominal cavity, or reduced-pressuretherapy.

As shown in FIG. 1, the abdominal treatment device 104 is disposedwithin the abdominal cavity 102 of the patient to treat the tissue site106. The abdominal treatment device 104 is supported by the abdominalcontents 108. The abdominal contents 108 include a surface on which theabdominal treatment device 104 is positioned. A portion 110 of theabdominal treatment device 104 may be positioned in or proximate to afirst paracolic gutter 112, and another portion 114 may be placed in orproximate to a second paracolic gutter 116.

The abdominal treatment device 104 is formed with a plurality ofliquid-impermeable layers 117, e.g., a first liquid-impermeable layer118 and a second liquid-impermeable layer 120. FIG. 1 is a schematicdrawing and is not to scale. The plurality of liquid-impermeable layers117, e.g., layers 118, 120, is formed with fenestrations 122, 124,respectively. “Liquid impermeable” with respect to “liquid-impermeablelayers” means that the layers are formed with a liquid-impermeablematerial. Thus, although formed with a liquid-impermeable material, thelayer may be liquid permeable when fenestrated, but nonetheless isreferred to as a liquid-impermeable layer. The fenestrations 122, 124may take any shape, e.g., circular apertures, rectangular openings,polygons, or any other shape. The fenestrations 122, 124 are presentedin this illustrative embodiment as slits, or linear cuts. As describedmore fully below, a foam spacer 125 is disposed between at least twolayers of the plurality of liquid-impermeable layers, e.g., the firstliquid-impermeable layer 118 and the second liquid-impermeable layer120. In considering FIG. 1, note that the portion of the abdominaltreatment device 104 shown is based on a cross section taken along lineA-A in FIG. 2. The abdominal treatment device 104 has a first side 105and a second, tissue-facing side 107. The abdominal treatment device 104is typically symmetrical such that the sides 105, 107 are same.Reference to different sides of the abdominal treatment device 104 ismade for explanation purposes.

A manifold 126, or manifold pad, distributes reduced pressure to theabdominal treatment device 104. A sealing member 128 provides a fluidseal over the abdominal cavity 102. One or more skin closure devices maybe placed on a patient's epidermis 130.

A reduced-pressure connector subsystem 132 may be used to fluidlyconnect the abdominal treatment device 104 to a reduced-pressure conduit134. The reduced-pressure connector subsystem 132 may include areduced-pressure connector 136, or interface, and the manifold 126.Alternatively, the reduced-pressure connector subsystem 132 may be an insitu connector (not shown) on the abdominal treatment device 104 or anyother device for supplying reduced pressure to the abdominal treatmentdevice 104. The reduced-pressure conduit 134 is fluidly coupled to areduced-pressure source 138.

Thus, in one illustrative embodiment, reduced pressure is delivered tothe abdominal treatment device 104 through the manifold 126 whichreceives reduced pressure through the reduced-pressure connector 136,which is coupled to the reduced-pressure delivery conduit 134. Thereduced-pressure source 138 delivers reduced pressure to thereduced-pressure delivery conduit 134.

The reduced pressure may be applied to the tissue site 106 to helppromote removal of ascites, exudates, or other fluids from the tissuesite 106. In some instances, reduced pressure may be applied tostimulate the growth of additional tissue. In some instances, only fluidremoval may be desired. As used herein, “reduced pressure” generallyrefers to a pressure less than the ambient pressure at a tissue sitethat is being subjected to treatment. In most cases, this reducedpressure will be less than the atmospheric pressure at which the patientis located. Alternatively, the reduced pressure may be less than ahydrostatic pressure at the tissue site. Reduced pressure may initiallygenerate fluid flow in the manifold 126, the reduced-pressure deliveryconduit 134, and proximate the tissue site 106. As the hydrostaticpressure around the tissue site 106 approaches the desired reducedpressure, the flow may subside, and the reduced pressure may bemaintained. Unless otherwise indicated, values of pressure stated hereinare gauge pressures. Although the terms “vacuum” and “negative pressure”may be used to describe the pressure applied to the tissue site, theactual pressure applied to the tissue site may be more than the pressurenormally associated with a complete vacuum. Consistent with the useherein, unless otherwise indicated, an increase in reduced pressure orvacuum pressure typically refers to a relative reduction in absolutepressure.

The manifold 126 is shown adjacent to the abdominal treatment device104. The manifold 126 may take many forms. The term “manifold” as usedherein generally refers to a substance or structure that is provided toassist in applying reduced pressure to, delivering fluids to, orremoving fluids from the tissue site 106 or other location. The manifold126 typically includes a plurality of flow channels or pathways thatdistribute the fluids provided to and removed around the manifold 126.In one illustrative embodiment, the flow channels or pathways areinterconnected to improve distribution of fluids provided or removedfrom the tissue site 106. The manifold 126 may be a biocompatiblematerial that is capable of being placed in contact with tissue site.Examples of the manifold 126 may include, without limitation, devicesthat have structural elements arranged to form flow channels, cellularfoam, such as open-cell foam, porous tissue collections, liquids, gelsand foams that include or cure to include flow channels. The manifold126 may be porous and may be made from foam, gauze, felted mat, or anyother material suited to a particular biological application.

In one embodiment, the manifold 126 is a porous foam and includes aplurality of interconnected cells or pores that act as flow channels.The porous foam may be a polyurethane, open-cell, reticulated foam, suchas a GranuFoam® material manufactured by Kinetic Concepts, Incorporatedof San Antonio, Tex. Other embodiments might include “closed cells.” Insome situations, the manifold 126 may also be used to distribute fluids,such as medications, antibacterials, growth factors, and varioussolutions to the tissue site 106 or to another location. Other layersmay be included in or on the manifold 126, such as absorptive materials,wicking materials, hydrophobic materials, and hydrophilic materials. Thefoam spacer 125 in the abdominal treatment device 104 may be made fromany of the same materials as the manifold 126. For example, and not byway of limitation, the foam spacer 125 may be a polyurethane, open-cell,reticulated foam, such as a GranuFoam® material.

The sealing member 128 is placed over the abdominal cavity 102 andprovides a fluid seal. As used herein, “fluid seal,” or “seal,” means aseal adequate to maintain reduced pressure at a desired site given theparticular reduced-pressure source 138 or subsystem involved. Thesealing member 128 may be a cover that is used to secure the manifold126 on a portion of the abdominal treatment device 104. The sealingmember 128 may be impermeable or semi-permeable. The sealing member 128is capable of maintaining reduced pressure at the tissue site 106 afterinstallation of the sealing member 128 over the abdominal cavity 102 andparticularly an abdominal cavity opening 140. The sealing member 128 maybe a flexible over-drape or film formed from a silicone-based compound,acrylic, hydrogel or hydrogel-forming material, or any otherbiocompatible material that includes the impermeability or permeabilitycharacteristics as desired for applying reduced pressure to the tissuesite 106.

The sealing member 128 may further include an attachment device 142 tosecure the sealing member 128 to the patient's epidermis 130. Theattachment device 142 may take many forms. For example, the attachmentdevice may be an adhesive layer 144 that may be positioned along aperimeter, the entirety of, or any portion of the sealing member 128 toprovide, directly or indirectly, the fluid seal with the patient'sepidermis 130. The adhesive layer 144 may also be pre-applied to thesealing member 128 and covered with a releasable backing, or member (notshown), that is removed at the time of application.

The reduced-pressure connector 136 may be, as one example, a port orconnector, which permits the passage of fluid from the manifold 126 tothe reduced-pressure delivery conduit 134 and vice versa. For example,fluid collected from the tissue site 106 using the manifold 126 and theabdominal treatment device 104 may enter the reduced-pressure deliveryconduit 134 via the reduced-pressure connector 136. In anotherembodiment, the system 100 may omit the reduced-pressure connector 136and the reduced-pressure delivery conduit 134 may be inserted directlyinto the sealing member 128 and into the manifold 126. Thereduced-pressure delivery conduit 134 may be a medical conduit or tubingor any other device for transporting a reduced pressure and fluid. Thereduced-pressure delivery conduit 134 may be a multi-lumen member. Inone embodiment, the reduced-pressure delivery conduit 134 is a two-lumenconduit with one lumen for reduced pressure and liquid transport and onelumen for communicating pressure to a pressure sensor.

Reduced pressure is supplied to the reduced-pressure delivery conduit134 by the reduced-pressure source 138. A wide range of reducedpressures may be supplied by the reduced-pressure source 138. In oneembodiment, the pressure may be in the range −50 to −300 mm Hg and inanother embodiment, in the range of −100 mm Hg to −200 mm Hg. Thepressure may be, for example, −100, −110, −120, −125, −130, −140, −150,−160, −170, −180, −190, or −200 mm Hg. In one illustrative embodiment,the reduced-pressure source 138 includes preset selectors for −100 mmHg, −125 mm Hg, and −150 mm Hg. The reduced-pressure source 138 may alsoinclude a number of alarms, such as a blockage alarm, a leakage alarm,or a battery-low alarm. The reduced-pressure source 138 could be aportable source, wall source, or other unit for abdominal cavities. Thereduced-pressure source 138 may selectively deliver a constant pressure,varied pressure (patterned or random), intermittent pressure, orcontinuous pressure. The fluid removed from the cavity through thereduced-pressure delivery conduit 134 could be as much as 5 L or moreper day depending on the circumstances. A canister or fluid reservoirfor receiving removed fluids may be associated with the reduced-pressuresource 138.

A number of different devices, e.g., device 146, may be added to aportion of the reduced-pressure delivery conduit 134. For example, thedevice 146 may be a fluid reservoir, or canister collection member, apressure-feedback device, a volume detection system, a blood detectionsystem, an infection detection system, a filter, a flow monitoringsystem, a temperature monitoring system, or other device. Multipledevices 146 may be included. Some of these devices, e.g., the fluidcollection member, may be formed integrally with the reduced-pressuresource 138.

Referring now primarily to FIGS. 2 and 3, the abdominal treatment device104 is flexible and easily positioned within the abdominal cavity. Atthe same time, the abdominal treatment device 104 is adapted to avoidblockage at discrete locations on the abdominal treatment device 104 byhaving fluid flow over a large range of directions. In order tofacilitate flexibility, the abdominal treatment device 104 may be formedwith the foam spacer 125 smaller than the liquid-impermeable layers 117.

The abdominal treatment device 104 includes the plurality ofliquid-impermeable layers 117, e.g., the first liquid-impermeable layer118 and the second liquid-impermeable layer 120. The micro-channel 168space is formed between adjacent layers of the plurality ofliquid-impermeable layers 117. Additional layers may be included in theplurality of liquid-impermeable layers 117. The plurality ofliquid-impermeable layers 117 is formed with fenestrations, e.g.,fenestrations 122, 124, and the layers of the plurality ofliquid-impermeable layers 117 are placed proximate to one another toform a substantially flat member having a co-extensive area A₁.

The coextensive area A₁ is the plan view area (before insertion) ofwhere the layers of the plurality of liquid-impermeable layers 117 thatare adjacent to the foam spacer 125 are co-extensive with one another.The foam spacer 125 is disposed between at least two layers of theplurality of liquid-impermeable layers 117. The plurality ofliquid-impermeable layers 117 may be formed from the same materials asthe sealing member 128. In one embodiment, each of theliquid-impermeable layers 117 may be of a thickness in the range of 50to 120 microns and in another non-limiting embodiment may beapproximately 80 microns.

The foam spacer 125 has a plan-view area A₂, e.g., the area shown inplan view, that is less than the coextensive area A₁ of the plurality ofliquid-impermeable layers 117. The plan-view area A₂ is less than thecoextensive area A₂ of the plurality of liquid-impermeable layers 117 atleast in part to enhance flexibility. Typically, the plan-view area A₂is less than 80percent (80%) of the coextensive area A₁ of the pluralityof liquid-impermeable layers 117, i.e. A₂<0.8A₁. The plan-view area A₂may be less of a percentage of A₁, e.g., A₂<0.7A₁, A₂<0.6A₁, A₂<0.5A₁,A₂<0.4A₁, A₂<0.3A₁, A₂<0.2A₁, A₂<0.1A₁, etc.

A plurality of bonds 160 may be used to couple at least two layers ofthe plurality of liquid-impermeable layers 117. Any pattern or randombonds may be used for the plurality of bonds 160. The bonds may beformed using any known technique, including without limitation, welding(e.g., ultrasonic or RF welding), bonding, adhesives, cements, or otherbonding technique or apparatus. The plurality of bonds 160 may includespacer bonds 162 that may be around or surround edges 164 of the foamspacer 125 as shown in plan view. The spacer bonds 162 may be a stitchbond as shown in FIG. 2 or a solid bond as shown in FIG. 5. The spacerbonds 162 help secure the foam spacer 125 in a fixed position relativeto the plurality of liquid-impermeable layers 117.

The fenestrations, e.g., fenestrations 122, 124, allow fluids to enterthe space between the plurality of liquid-impermeable layers 117. Thefluids that enter the fenestrations 122, 124 move directly or indirectlytowards a reduced-pressure source. A reduced pressure may be, andtypically is, applied to a center portion 166 of the abdominal treatmentdevice 104 or elsewhere to cause fluid flow through the fenestrations122, 124 and within the foam spacer 125 or micro-channels 168 (FIG. 3)formed between adjacent layers of the plurality of liquid-impermeablelayers 117. Typically, the foam spacer 125 communicates reduced pressurewithin the plurality of liquid-impermeable layers 117 and often will bea dominant source of reduced-pressure. The reduced pressure at variouslocations may be represented by pressure vectors, e.g., reduced-pressurevectors 156 (FIG. 2).

While flexibility is desired for the abdominal treatment device 104,blockage avoidance is also desired. If an abdominal device 104 only hada center portion 166, a point in the micro-channel 168, or betweenliquid impermeable layers, would experience reduced pressure movingfluids in substantially one direction, or over a limited angle dependingon its distance from the center portion 166. If that unidirectional pathbecomes blocked, the flow in a particular area may largely stop. Thepresent embodiment of the abdominal treatment device 104 deliversreduced pressure over a large angle, e.g., 270-360 degrees, for a givenpoint. Typically, reduced pressure is experienced in all directions (360degrees). The foam spacer 125 provides the strongest source of reducedpressure within the micro-channels 168 and influences the flowdirections.

Referring to FIGS. 2 and 3, consider a cylindrical analytical controlvolume 158, which is a control volume for analyzing pressure at alocation in the micro-channel 168. The control volume 158 experiencesreduced pressure over 360 degrees. The abdominal treatment device 104may have all the analytical control volumes, e.g., analytical controlvolume 158, within a treatment area, or target fluid removal zone,experiencing 360 degrees of reduced pressure. Thus, if a blockage occursin one direction for an analytical control volume, fluid may continue tomove in other directions. The angle over which the reduced pressure actson a given analytical control volume, e.g., analytical control volume158, is defined as angle theta (θ).

The area of the abdominal treatment device 104 that experiences greaterthan 270 degrees of reduced pressure may be defined as a target fluidremoval zone. For example, the area may experience 270, 280, 290, 300,310, 320, 330, 340, 350, or 360 degrees of reduced pressure. The targetfluid removal zone is generally defined as the area bound substantiallyby an outer peripheral edge of the foam spacer 125 making allowances forany discontinuities. Thus, for the abdominal treatment device of FIG. 2,the target fluid removal zone exists on the portion of the abdominaltreatment device 104 that is inboard from a peripheral edge 150 by adistance 152. In other words, the target fluid removal zone is from aperipheral edge 167 of the foam spacer 125 (or from the outer edge of aconcentric circle 154) and inward. In other illustrative embodiments,the target fluid removal zone may have portions in which the analyticalcontrol volumes would have an angle theta (θ) less than 360 degrees,e.g., 270 degrees, but preferably the majority, i.e., >50%, of locationsanalyzed will have 360 degrees of reduced pressure acting upon them. Inother embodiments, the target flow zone may be defined as having morethan 70 percent (70%) of the locations experiencing reduced pressure in360 degrees. As shown in FIG. 2, the foam spacer 125 may be formed witha plurality of windows or window openings, such as where cylindricalanalytical control volume 158 is shown.

Referring now to FIGS. 4A and 4B, a portion of an abdominal treatmentdevice 104 is presented. The portion shows portions of a foam spacer 125under a first liquid-impermeable layer 118 having fenestrations 127. Thefirst liquid-impermeable layer 118 is bonded with bonds 160 to a secondliquid-impermeable layer 120 with the foam spacer 125 therebetween. Awindow 129 is formed by the foam spacer 125 in this portion of targetfluid removal zone. Because the foam spacer 125 of the window 129provides the main delivery of reduced pressure, an analytical controlvolume 158 experiences reduced pressure vectors 158 over angle theta of360 degrees.

Often, the reduced pressure in a given direction will be related to thedistance from the analytical control volume 158 to the foam spacer 125in a given direction. Thus, for FIG. 4A, a first reduced-pressure vector159 and a second reduced-pressure vector 161 are the greatest becausethey are at locations closest to the foam spacer 125. Third and fourthreduced-pressure vectors 163 and 165 are the least because they are thefarthest from the foam spacer 125 in a given direction.

The foam spacer 125 may take numerous possible shapes. The shape andsize of the foam spacer 125 are typically selected to promoteflexibility of the abdominal treatment device 104, i.e., to make theabdominal treatment device 104 compliant. The flexibility typicallyhelps place the abdominal treatment device 104 or a portion of theabdominal treatment device 104 in difficult-to-reach locations, such asthe paracolic gutters 112 and 116, and helps remove the abdominaltreatment device 104 in certain situations. With respect to the latter,the abdominal treatment device 104 may be applied in some situationsthrough an open abdomen with a directly connecting reduced-pressuredelivery conduit 134, the abdominal cavity opening 140 closed, and thenlater the abdominal treatment device 104 may be removed through asurgical incision, e.g., an incision in the range of 5 centimeters to 40centimeters—or any sub-range thereof.

In addition to flexibility, the shape of the foam spacer 125 may beselected to promote a range of reduced-pressure vectors 156 in a targetflow zone or to direct flow. In the illustrative embodiment of FIG. 2,the foam spacer 125 is formed as a plurality of arced members, e.g.,concentric circles or elliptical members, 170 that are interconnected bymembers 172. The target treatment zone may experience 360 degrees ofreduced pressure. FIG. 5 presents another illustrative shape.

Referring now primarily to FIG. 5, the foam spacer 125 of the abdominaltreatment device 104 includes mirrored c-shaped members that areinterconnected. The foam spacer 125 is formed with spacer bonds 162 thatare one or more solid bonds. In this embodiment, analytical controlvolumes, such as analytical control volume 158, in the target flow zoneexperience reduced-pressure vectors 156 that may be less than 360degrees but greater than 270 degrees. Other points, e.g., interior point174, may experience 360 degrees of reduced-pressure vectors 156. Thetarget flow zone for this embodiment is inboard of the outer peripheraledge 167 of the foam spacer 125. A majority, e.g., >50%, of thelocations of the target flow zone experience reduced pressure in 360degrees and thereby help minimize the chance of blockage inhibitingflow. In other embodiments, the target flow zone may be defined ashaving more than 70 percent (70%) of the locations experiencing reducedpressure in 360 degrees.

As another non-limiting example of a shape that the foam spacer 125 ofthe abdominal treatment device 104 may take, FIG. 6 presents a foamspacer 125 formed as a plurality of interconnected, annular circles. Inthis embodiment, analytical control volumes (e.g., first analyticalcontrol volume 158 and second analytical control volumes 174),experience 360 degrees of reduced-pressure vectors 156. The spacer bonds162 are shown as a stitch bond in this example.

Referring now primarily to FIGS. 7 and 8, another illustrativeembodiment of an abdominal treatment device 104 is presented, but inthis embodiment, control of the direction of the reduced pressure isdesired. The foam spacer 125 is formed as a star with a plurality ofspaced leg members 178. Longitudinal bonds 182 have been added to directfluid flow in a particular direction. Fluids attracted by thisembodiment of the abdominal treatment device 104 primarily have flowalong the foam spacer 125 and along flow channels 184 formed by thelongitudinal bonds 182.

The foam spacer 125 is disposed between the first liquid-impermeablelayer 118 and second liquid-impermeable layer 120 of the plurality ofliquid-impermeable layers 117. A plurality of bonds 160, includingspacer bonds 162, are formed. The spacer bonds 162 around the peripherymay be excluded to leave an open intake space between the layers 118,120 at the periphery. The flow channels 180 are formed by placing thefirst longitudinal bonds 182 and the second longitudinal bonds 182 atdesired locations. The longitudinal bonds 182 and 184 may be formedradially outward from the center portion 166. The longitudinal bonds182, 184 may begin outboard of the center portion 166 as shown or may goall the way to the center portion 166. Flow channels 180 may be usedwhere increased or directed reduced pressure is more important thanguarding against blockage. Analytical control volume 186 shows thereduced pressure vectors may be oriented mainly toward the centerportion 166.

In one illustrative approach to using the system 100 for treating theabdominal cavity 102, the abdominal cavity 102 is opened and theabdominal treatment device 104 is deployed within the abdominal cavity102. The reduced pressure connector subsystem 132 may be fluidly coupledto the abdominal treatment device 104. The reduced pressure connectorsubsystem 132 may be fluidly coupled to the reduced-pressure source 138and the reduced-pressure source 138 activated. After use, the abdominaltreatment device 104 may be removed through the open abdomen or laterthrough a surgical incision.

The abdominal treatment device 104 may be manufactured, according to oneillustrative embodiment, by providing the plurality ofliquid-impermeable layers 117 that are fenestrated; stacking theplurality of liquid-impermeable layers 117; and disposing a foam spacer125 between at least two layers of the plurality of liquid-impermeablelayers 117. The plurality of liquid-impermeable layers 117 has acoextensive area A_(l). The foam spacer 125 disposed between at leasttwo layers of the plurality of liquid-impermeable layers 117 has aplan-view area A₂. A₂ is less than 80% of A₁ (i.e., A₂<0.8A₁). The foamspacer 125 is configured and positioned such that, under reducedpressure, a target fluid removal zone experiences reduced-pressurevectors over an angle theta (θ) that is greater than 90 degrees.

Although the present invention and its advantages have been disclosed inthe context of certain illustrative, non-limiting embodiments, it shouldbe understood that various changes, substitutions, permutations, andalterations can be made without departing from the scope of theinvention as defined by the appended claims. It will be appreciated thatany feature that is described in connection to any one embodiment mayalso be applicable to any other embodiment.

It will be understood that the benefits and advantages described abovemay relate to one embodiment or may relate to several embodiments. Itwill further be understood that reference to ‘an’ item refers to one ormore of those items.

The steps of the methods described herein may be carried out in anysuitable order, or simultaneously where appropriate.

Where appropriate, aspects of any of the examples described above may becombined with aspects of any of the other examples described to formfurther examples having comparable or different properties andaddressing the same or different problems.

It will be understood that the above description of preferredembodiments is given by way of example only and that variousmodifications may be made by those skilled in the art. The abovespecification, examples and data provide a complete description of thestructure and use of exemplary embodiments of the invention. Althoughvarious embodiments of the invention have been described above with acertain degree of particularity, or with reference to one or moreindividual embodiments, those skilled in the art could make numerousalterations to the disclosed embodiments without departing from thescope of the claims.

1. An abdominal treatment device for distributing reduced pressure to atissue site, the abdominal treatment device comprising: a plurality ofliquid-impermeable layers, wherein the liquid-impermeable layers are atleast partially fenestrated; a micro-channel space between theliquid-impermeable layers; a foam spacer disposed between at least twolayers of the liquid-impermeable layers, wherein the foam spacercomprises mirrored c-shaped members having an outer peripheral edge anda target flow zone inboard of the outer peripheral edge; and spacerbonds coupling at least two of the liquid-impermeable layers anddisposed along the outer peripheral edge of the c-shaped members; andwherein the micro-channel space in the target flow zone is adapted toexperience reduced-pressure vectors over an angle that is at least 270degrees.
 2. The abdominal treatment device of claim 1, wherein themirrored c-shape members are interconnected.
 3. The abdominal treatmentdevice of claim 1, wherein the spacer bonds comprise a stitch bond. 4.The abdominal treatment device of claim 1, wherein the spacer bondscomprise a solid bond.
 5. The abdominal treatment device of claim 1,wherein each of the liquid-impermeable layers has a thickness in therange of 50 to 120 microns.
 6. The abdominal treatment device of claim1, wherein: the mirrored c-shape members are interconnected; the spacerbonds comprise a solid bond; and each of the liquid-impermeable layershas a thickness in the range of 50 to 120 microns.
 7. An abdominaltreatment device for distributing reduced pressure to a tissue site, theabdominal treatment device comprising: a plurality of liquid-impermeablelayers, wherein the liquid-impermeable layers are at least partiallyfenestrated; a micro-channel space between the liquid-impermeablelayers; a foam spacer disposed between at least two layers of theliquid-impermeable layers, wherein the foam spacer comprises a pluralityof annular circles having an outer peripheral edge and a target flowzone inboard of the outer peripheral edge; and spacer bonds coupling atleast two of the liquid-impermeable layers and disposed along the outerperipheral edge of the foam spacer; and wherein the foam spacer isconfigured such that the micro-channel space in the target flow zoneexperiences reduced-pressure vectors over an angle that is at least 270degrees under reduced pressure.
 8. The abdominal treatment device ofclaim 7, wherein the annular circles are interconnected.
 9. Theabdominal treatment device of claim 7, wherein the spacer bonds comprisea stitch bond.
 10. The abdominal treatment device of claim 7, whereinthe spacer bonds comprise a solid bond.
 11. The abdominal treatmentdevice of claim 7, wherein each of the liquid-impermeable layers has athickness in the range of 50 to 120 microns.
 12. The abdominal treatmentdevice of claim 7, wherein: the annular circles are interconnected; thespacer bonds comprise a stitch bond; and each of the liquid-impermeablelayers has a thickness in the range of 50 to 120 microns.
 13. A systemfor treating an abdominal cavity with reduced pressure, the systemcomprising: an abdominal treatment device comprising: a plurality ofliquid-impermeable layers, wherein the plurality of liquid-impermeablelayers are at least partially fenestrated, a micro-channel space betweenthe liquid-impermeable layers; a foam spacer disposed between at leasttwo layers of the plurality of liquid-impermeable layers, the foamspacer and comprising a plurality of annular circles having an outerperipheral edge and a target flow zone inboard of the outer peripheraledge, and spacer bonds coupling at least two of the liquid-impermeablelayers and disposed along the outer peripheral edge of the foam spacer,wherein the foam spacer is configured so that the micro-channel spaceexperiences reduced-pressure vectors over an angle that is at least 270degrees under reduced pressure; and a reduced-pressure source fluidlycoupled to the abdominal treatment device.
 14. The system of claim 13,wherein the annular circles are interconnected.
 15. The system of claim13, wherein the spacer bonds comprise a stitch bond.
 16. The system ofclaim 13, wherein the spacer bonds comprise a solid bond.
 17. The systemof claim 13, wherein each of the liquid-impermeable layers has athickness in the range of 50 to 120 microns. 18.-20. (canceled)